Need help in Python3 - sockets

Question

I have the below code that i am trying the run using python3.2 interpreter.
import socket #for sockets
import sys #for exit
#from UserString import MutableString
#create an INET, STREAMing socket
try:
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
except socket.error:
print ('Failed to create socket')
sys.exit()
print ('Socket Created')
host = 'www.google.com';
port = 80;
try:
remote_ip = socket.gethostbyname( host )
except socket.gaierror:
#could not resolve
print ('Hostname could not be resolved. Exiting')
sys.exit()
#Connect to remote server
s.connect((remote_ip , port))
print ('Socket Connected to ' + host + ' on ip ' + remote_ip)
#Send some data to remote server
message = "GET / HTTP/1.0\r\n\r\n"
try :
#Set the whole string
s.sendall(message.encode())
except socket.error:
#Send failed
print ('Send failed')
sys.exit()
print ('Message send successfully')
#Now receive data
messageParts = []
remaining = 4096
chunk = s.recv(remaining)
messageParts.append(chunk)
while (len(chunk) > 0):
chunk = s.recv(remaining)
messageParts.append(chunk.decode())
finalMessage = b"".join(messageParts)
print('Printing the html contents ...')
print(finalMessage)
Upon running the above code, with python version 3.2, i get the below error:
Socket Created
Socket Connected to www.google.com on ip 74.125.201.147
Message send successfully
Traceback (most recent call last):
File "TestMainServerV2.py", line 73, in <module>
finalMessage = b"".join(messageParts)
TypeError: sequence item 1: expected bytes, str found
Could anybody let me know what is the issue?
Thanks!

Answer 1

messageParts.append(chunk.decode())
is appending strs to messageParts.
chunk = s.recv(remaining)
messageParts.append(chunk)
is appending bytes to messageParts. (Everything that comes through a socket is bytes so chunk is a bytes object.)
Especially in Python3, one should never mix strs and bytes.
b"".join(messageParts)
raises a TypeError since b"".join expects only bytes.
You can avoid the problem by not decoding chunk. Use
messageParts.append(chunk)
instead of
messageParts.append(chunk.decode())